1. Field of the Invention
The present is generally related to a method for attenuating the sound emanating from an outboard motor engine and also providing a heat sink for the engine and, more particularly, to a water reservoir shaped to cover certain preselected regions of the engine.
2. Description of the Prior Art
Liquid reservoirs are used for various purposes in conjunction with engines known to those skilled in the art. U.S. Pat. No. 6,056,611, which issued to House et al on May 2, 2000, discloses an integrated induction noise silencer and oil reservoir. The reservoir is used as a sound attenuator in an outboard motor and is placed under the cowl of the outboard motor with the throats of the engine""s throttle bodies disposed between the oil reservoir and the engine itself. This allows the sound emanating from the throttle bodies to be attenuated by the oil reservoir which is cup-shaped to partially surround the throat of the throttle bodies. A plate member can be attached to a hollow wall structure in order to enclose a cavity therebetween. The structure therefore serves as an oil reservoir for the engine and also as a sound attenuating member.
U.S. Pat. No. 4,513,696, which issued to Fujii on Apr. 30, 1985, describes an apparatus for charging cooling liquid to engine cooling system. The apparatus comprises an additive reservoir for storing an additive such as an anti-icing agent, a cooling water reservoir for storing cooling water, a filler head adapted to be connected with an coolant inlet of an automobile engine cooling system, additive conduits extending between the additive reservoir and the filler head, cooling water conduits extending between the cooling water reservoir. Additive control valves are provided in the additive conduits for controlling the quantity of the additive supplied to the engine cooling system in accordance with the capacity of the cooling system and a desired concentration of the additive. Cooling water control valves are also provided in the cooling water conduits for controlling the quantity of cooling water supplied to the engine cooling system in accordance with the capacity of the cooling system and the desired concentration of the additive, whereby the cooling water is charged to the engine cooling system with the desired concentration of the additive.
U.S. Pat. No. 4,566,171, which issued to Fukami et al on Dec. 3, 1985, describes a heating system for automobiles with heat storage tank. The system utilizes the hot water from the engine cooling system as a heat source and includes a heating radiator and a heat accumulating water tank, and pipe lines are provided between the engine cooling system, heating radiator, and heat accumulating water tank. The flow passages of the cooling water through the pipe lines are switched by electromagnetic valves provided in the pipe lines so that the heating radiator and the heat accumulating water tank are connected in series or in parallel with each other with respect to the engine cooling system, or a circulating passage is formed between the heating radiator and the heat accumulating water tank. The heat accumulating water tank has a mixing preventing device to prevent cold cooling water flowing into the water tank from mixing with hot water contained in the water tank.
U.S. Pat. No. 5,149,284, which issued to Kawai on Sep. 22, 1992, describes an exhaust system for an outboard motor. The device is adapted to be embodied in an outboard motor that is comprised of a power head having an internal combustion engine surrounded by a protective cowling. The engine includes an exhaust port in communication with an exhaust pipe for discharging exhaust gases from the engine. A steering shaft is affixed to the drive shaft housing by upper and lower connections which include elastic bushings. An upper reservoir receives cooling water from the engine to cool structures adjacent the exhaust pipe and specifically the elastic bushings. The reservoir is dammed up on the forward side by the bushing and receives cooling form the cooling water.
U.S. Pat. No. 5,439,404, which issued to Sumigawa on Aug. 8, 1995, describes a cooling system for an outboard motor. The cooling system is intended to provide cooling for an outboard motor and specifically for the lubricating reservoir thereof. The lubricating reservoir depends into the drive shaft housing and is surrounded by an open trough-like water manifold to which cooling water is delivered from the engine. The manifold has lower restrictive openings which direct the coolant to the outer peripheral wall of the oil pan of the lubricant reservoir. The water level is maintained by a weir-like structure and the water that overflows the weir is also directed toward the outer surface of the lubricant reservoir.
Two problems exist in relation to outboard motors. First, noise emanates from various portions of the engine of an outboard motor and, when the level of noise exceeds certain limits, the enjoyment of the use of a marine vessel propelled by the outboard motor is affected. A second problem relating to outboard motors is that, under certain conditions, heat from the engine block and cylinder head portion of the engine raises the temperature of the fuel system components after the engine is turned off. Also, in four cycle engines, heat from an oil sump can also raise this temperature. If this increased temperature of the fuel system components causes vaporization of the fuel within those components, vapor lock can result.
It would therefore by significantly beneficial if a means could be provided to reduce the vapor lock problem and to reduce the sound emanating from the engine. It would be particularly beneficial if a common device could be provided which addresses both problems by attenuating the sound emanating from the engine of an outboard motor while also absorbing heat from the engine, when the engine is turned off, and preventing that heat from raising the temperature of fuel within the fuel system of the engine.
An outboard motor made in accordance with a preferred embodiment of the present invention comprises a water cooled engine having at least one cooling passage formed within the engine. It further comprises a water pump for drawing water from a body of water and causing the water to flow through the cooling passage of the engine. In addition, a preferred embodiment of the present invention further comprises a water reservoir that is connected in fluid communication between the water pump of the outboard motor and the cooling passage within the water cooled engine. The reservoir is shaped to define a plurality of water containment cavities, in which each of the water containment cavities is connected in fluid communication with at least one other of the plurality of water containment cavities. The reservoir is attachable to the engine in order to dispose a first one of the plurality of water containment cavities proximate a first surface portion of a first side of the engine and to further dispose a second one of the plurality of water containment cavities proximate a second surface of a second side of said engine.
The reservoir can be connected in fluid communication with a water pump by a first tube and also connected in fluid communication with the cooling passage by a second tube. The reservoir can also be shaped to dispose a third one of the plurality of water containment cavities proximate a third surface portion of a third side of the engine. The first, second, and third sides of the engine can be the top side, port side, starboard side, front side, or rear side, in any preselected combination. The first surface portion of the engine can be a sound producing portion, such as an exhaust manifold or intake manifold, or a heat producing portion of the engine, such as an exhaust manifold or cylinder head portion of the engine.